Compound block.



No. 784,158. PATBNTED MAR. '7, 1905. L. G. HALLBERG.

COMPOUND BLOCK.

APPLICATION FILED APR. 24, 1903.

FIG. 1. w

Q69 VE N 70/? A 7TOHNE Y3 UNITED STATES Patented March '7, 1905.

PATENT OFFICE.

.ooMPou D BLOCK.

SPECIFICATION forming part of Letters Patent No. 784,158, dated March '7, 1905.

Application filed April 24, 1903. Serial No. 154,079.

To all whom it may concern:

Be it known that I, LAWRENCE GUSTAV HALLBERG, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Compound Blocks, of which the following is a specification.

My invention relates to an improved compound block which is especially designed for use in making fireproof floor and ceiling constructions; and it consists of a new and im proved compound cement and metal block or tile having certain novel features, as hereinafter described and claimed.

In the drawings accompanying this specification, Figure 1 is an isometric perspective view of a portion of a flooring or ceiling with the supporting wall and beam or girder, showing blocks or tiles constructed in accordance with my invention. Fig. 2 is a view similar to Fig. l, but showing a slightly-modified form of block or tile. Fig. 3 is a side view of one of the blocks constructed in accordance with my invention, and Fig. 4c is an end view thereof.

In the drawings the reference-letter A indicates a suitable wall, and-B indicates a suitable beam or girder forming the supports or rests upon which the blocks are carried. It is of course understood that the blocks may be suitably supported by any convenient means and with any arrangement of Walls, girders, or beams, and I have shown the forms ind icated in the drawings merely as arbitrary and convenient illustrations of this general plan. It is also to be understood that the blocks may be employed in any other suitable manings I have shown two forms, those of Fig. 1 being substantially IF-shaped and adapted for use where ribbed ceilings are desired and those of Fig. 2 being in hollow form and adapted for use where smooth ceilings are employed.

In any form in which the blocks are embodied 1 embed longitudinal anchorrods in the material thereof, which are provided with any suitable means to prevent the rods from slipping and becoming displaced in the material or to prevent the rods and material from moving relatively to each other. The rods 0 extend in substantially straight lines, are preferably located near the base of the blocks, and are provided with heads 0' to securely anchor them. The curved rods also provided with anchors, such as the heads 0', are embedded in the material above the straight rods, and when blocks having vertical walls or ribs or webs are employed the rods are arranged in the webs or ribs. The rods 0 are suitably bent or sagged, being preferably arranged in an approximately catenary curve. The rods or bars furnish tensile resistance to the compressive stresses of the concrete, and their tensile stress or resistance is substituted for the mere resistance to transverse strain of the material of the block, whereby they prevent any buckling down or fracture of the blocks when weight or load is applied thereto. It is obvious that the application of weight or load will cause a stress or strain in the longitudinal lines of the rods or against their tensile resistance, whereby the stress is ,to draw the rods longitudinally, which is opposed by the most effective resistance inherent in the rods, so that they increase the resistance of the blocks, as they cannot be drawn out or lengthened. Moreover, the bent rods prevent shearing of the material either vertically or longitudinally, and as they represent the catenary line which the weight would take if no resistance medium like the cement or concrete were present they hold the material together in the most eiiective manner.

It is apparent that each block or tile provided with its strengthening-rods is a unitary structure which may be made complete and tested at the factory instead of being constructed a site at the place of use, so that in erecting a building there is no delay while the cement sets; but the finished blocks may be easily and rapidly placed and a cement floor or ceiling may be quickly laid. W hen a floor is laid, the cement or other covering, as

D, may be placed thereon immediately and anchor-rod also embedded in said wall above the floor-tiles set in it or the sleepers or strips the straight rod, the said rods extending sub- (Z embedded or dovetailed into the cement, to stantially the length of the beam and being which the flooring-boards d are nailed. provided with heads at the ends thereof. 5 Having described my invention, I claim i In testimony whereof I affix my signature in 5 A unitary structure of the class described, presence of two witnesses.

consisting of a hollow rectangular beam com- LAWRENCE G. HALLBERG. posed of cementitious material, a straight Witnesses: anchor-rod embedded in each side Wall of the E. MOLITOR,

IO beam near the base thereof, and a sagged J. MoRoBER'rs. 

